“If you’d have said to me five fights ago that Anthony would be fighting Wladimir Klitschko in his 19th fight for two belts at Wembley in front of 90,000, I would’ve said no chance,” Hearn said. “I believe Anthony and Wladimir have both had good camps, so it’s just going to come down to who can deal with the pressure on the night. I’ve never seen a fighter as calm as Anthony going into a fight like this. I’m nervous. I’m petrified. Yet he remains calm. I think Wladimir will do all that he can to get into Anthony’s head. If Anthony can remain in the same mindset that he is at the moment, I’m very confident of victory.”

Back in May 2014, Hearn promoted another blockbuster bout at Wembley Stadium, when he matched Carl Froch with George Groves in a fierce domestic grudge rematch. Despite the significant success of this promotion, the Matchroom chief believes that it will be dwarfed by the Joshua-Klitschko event.

“This fight is on another level to Froch-Groves. The international TV is going to more territories than ever before, and I believe that the pay-per-view will break all-time records,” Hearn stated. “If Anthony can remain chilled, then he’s not human! The pressure that will come on fight night will be huge. I believe that victory against Klitschko makes him the biggest star in British sport, and probably the biggest star in world boxing.”

Having already reached such a lofty level in the sport after just three-and-a-half years as a professional, it is difficult to know what IBF champ Joshua can do next to surpass his monster meeting with Klitschko this weekend. It is something that has certainly got Hearn thinking outside the box.

Eddie commented: “Anthony said to me the other day that he wants to keep going [in boxing] for 10 years. I thought to myself, ‘Blimey, you’re fighting Wladimir Klitschko in front of 90,000 people, and you want 10 years!’ So how does that journey evolve over 10 years? I think it evolves by fighting in different markets. It’s the only way you can do it. You can’t keep going in England for 10 years – you’re going to run out of opponents. So I think the challenge will be to break down barriers in new markets, whether it’s Africa, the Far East, the Middle East, or America. That’s the natural progression.

“He probably can’t go back to an arena fight now. It’s like any job, isn’t it? How can you earn the sort of money he’ll earn against Klitschko, then take another fight for a third of that money? It just doesn’t work like that. Who is next? That’s the concern. You look at Deontay Wilder, Joseph Parker, Tyson Fury.”

As well as mentioning the likes of Wilder, Parker and Fury as potential future opponents for Joshua, Hearn also refused to dismiss a possible rematch with Klitschko, although he was keen to stress that it all depends on the outcome of this Saturday’s match.

“If the fight ends in a round, and no one wants to see it again, [a rematch] ain’t happening,” Hearn remarked. “But if it’s a great fight, and there’s an opportunity for everyone to make money again, then I wouldn’t rule [a rematch] out.”